Parasites and Female Choice in the Ring-necked Pheasant

The Hamilton and Zuk hypothesis is based on several assumptions:1) The parasites adversely affect host fitness, and susceptibilityto parasites is heritable. 2) Expression of secondary sexualcharacteristics is, at least to some extent, dependent on hostcondition and vigor, and therefore on host ability to controlparasites. 3) Females evolve appropriate discriminatory preferencefor secondary sexual characteristics that best reveal susceptibilityto parasites. This paper presentsthe results of experimentsdesigned to test these assumptions, using the Ring-necked Pheasant,Phasianus colchicus. The results show that resistance to diseasecan be heritable. Preliminary analysis of the mate choice testsdoes not reveal that these resistant offspring have better developedsecondary sexual characters, or that females prefer them. However,there is a correlation between display rate; coccidian parasiteload, and female choice in male pheasants.